Image recording apparatus

Abstract

An ink jet printer has a carriage equipped with a recording head. The carriage is disposed downstream in a feeding direction of a recording medium. The carriage has an optical sensor for measuring dirt on a supply roller. When the supply roller is dirty, a cleaning operation is started to rotate the supply roller as being pressed onto a separation pad. The dirt on the supply roller is measured with the optical sensor, and the cleaning operation lasts until the dirt is removed from the supply roller.

1. An image recording apparatus for recording an image on a sheet-like recording medium using a recording head located to a recording position, comprising:
 a supply roller for feeding said recording medium to said recording position; 
 a cleaning member for removing dirt from a peripheral surface of said supply roller; 
 a carriage holding said recording head, and moving back and forth in a main scanning direction orthogonal to a feeding direction of said recording medium; 
 a dirt measuring sensor attached to said carriage, and for measuring dirt on said peripheral surface of said supply roller; and 
 a cleaning controller for rotating said supply roller as being pressed onto said cleaning member and monitoring said dirt with said dirt measuring sensor during a cleaning operation, and for stopping said supply roller to finish said cleaning operation when said dirt is removed. 
 
     
     
       2. The image recording apparatus of  claim 1  further comprising a pressure plate for holding a stack of recording media, and for pressing the uppermost recording medium onto said supply roller,
 wherein said cleaning member is attached to said pressure plate. 
 
     
     
       3. The image recording apparatus of  claim 2 , wherein said carriage includes a projecting part which hangs over said supply roller, and said dirt measuring sensor is attached to an under surface of said projecting part. 
     
     
       4. The image recording apparatus of  claim 3 , wherein said recording head is an ink jet recording head which ejects droplets of ink to said recording medium. 
     
     
       5. The image recording apparatus of  claim 1  further comprising an annular groove extending in a circumferential direction on said peripheral surface of said supply roller,
 wherein said dirt measuring sensor measures first dirt on said peripheral surface and second dirt on a floor of said annular groove while said carriage moves in said main scanning direction, and 
 wherein said cleaning controller compares said first dirt with said second dirt to judge whether or not said dirt of said supply roller is removed. 
 
     
     
       6. The image recording apparatus of  claim 1 , further comprising:
 a roller rotation counter for counting the number of rotations of said supply roller during said cleaning operation; and 
 a first notification device for notifying that said supply roller needs to be replaced in the event that said roller rotation counter counts up to a predetermined number during said cleaning operation. 
 
     
     
       7. The image recording apparatus of  claim 6 , wherein said dirt measuring sensor measures dirt on said supply roller every time said supply roller rotates a predetermined number of times. 
     
     
       8. The image recording apparatus of  claim 1 , further comprising:
 a change rate calculator for calculating a rate of temporal change of dirt on said supply roller during said cleaning operation; and 
 a second notification device for notifying that said supply roller has deteriorated in the event that a calculated rate in said change rate calculator is below a predetermined rate of change. 
 
     
     
       9. The image recording apparatus of  claim 1 , further comprising:
 a memory storing information about how much dirt said supply roller comes to have in feeding a recording medium, according to the types of recording media; 
 an input device for entering the number of said recording media to be recorded serially; 
 an estimator for estimating degree of dirt with reference to said information in said memory and based on a measurement result of said dirt measuring sensor, the type of recording medium and said number of recording media to be recorded; and 
 a third notification device for notifying that said cleaning operation needs to be performed in advance of an image recording operation in the event that an estimated degree of dirt is on or above a predetermined threshold value. 
 
     
     
       10. An image recording apparatus for recording an image on a sheet-like recording medium using a recording head located to a recording position, comprising:
 a supply roller for feeding said recording medium to said recording position; 
 a cleaning member for making contact with said supply roller to remove dirt from a peripheral surface thereof during a cleaning operation of said supply roller; 
 a memory storing information about how much dirt said supply roller comes to have in feeding a recording medium, according to the types of recording media; 
 a dirt measuring sensor for measuring dirt on said supply roller; 
 an input device for entering the number of said recording media to be recorded serially; 
 an estimator for estimating degree of dirt with reference to said information in said memory and based on a measurement result of said dirt measuring sensor, the type of recording medium and said number of recording media to be recorded; and 
 a third notification device for notifying that said cleaning operation needs to be performed in advance of an image recording operation in the event that an estimated degree of dirt is on or above a predetermined threshold value.